Vehicles operating in an autonomous mode (e.g., driverless) can relieve occupants, especially the driver, from some driving-related responsibilities. When operating in an autonomous mode, the vehicle can navigate to various locations using onboard sensors, allowing the vehicle to travel with minimal human interaction or in some cases without any passengers.
Similar to human beings making various decisions while driving, an autonomous vehicle always has to make instant driving decisions according to the actual surrounding environment, which includes, but is not limited to, signal lights, traffic conditions, safety regulations, nearby pedestrians and vehicles, etc. When a human being drives a vehicle, he/she implicitly acknowledges the existence of each perceived object and associates a decision with each object. Thus, the actual decision outcome of human drivers is from a complicated and synthesized procedure, where individual decisions towards each object are consolidated and synthesized into a final decision which transforms into the anticipated trajectory of the vehicle and hence the actual handing of a steering-wheel, brake, and/or throttle. It is challenging to emulate such a thinking process in an autonomous vehicle.